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US 11,381,076 B2Granted
AC controlled relay drive circuit
AssigneeThe Vollrath Company, L.L.C.
InventorDonald Zahrte, Sr.
Life of this patent
Estimating the term…
Abstract
A drive circuit includes a voltage input circuit, a first surge protection device, and a second surge protection device. The voltage input circuit includes a first line terminal and a second line terminal, and supplies an input voltage to the first and second line terminals. The first surge protection device is connected between the first line terminal and ground to connect the first line terminal to ground when the input voltage is supplied, and to disconnect the first line terminal from ground when the input voltage is not supplied. The second surge protection device is connected between the second line terminal and ground to connect the second line terminal to ground when the input voltage is supplied, and to disconnect the second line terminal from ground when the input voltage is not supplied.
Claims18
A drive circuit comprising:
- a voltage input circuit comprising a first line terminal and a second line terminal, the voltage input circuit configured to supply an input voltage to the first and second line terminals, wherein the voltage input circuit is an alternating current (AC) input circuit, and the input voltage corresponds to an AC input;
- a first surge protection device coupled between the first line terminal and ground;
- a second surge protection device coupled between the second line terminal and ground;
- and
- a relay circuit comprising a switch and powered by the voltage input circuit and configured to:
- connect the first line terminal to ground when the input voltage is supplied, and to disconnect the first line terminal from ground when the input voltage is not supplied;
- and
- connect the second line terminal to ground when the input voltage is supplied, and to disconnect the second line terminal from ground when the input voltage is not supplied;
- and
- a bridge rectifier capacitively coupled to the first and second line terminals, the bridge rectifier configured to convert the AC input to a direct current (DC) output for operating the switch, wherein the switch is controlled in response to the DC output and configured to electrically isolate each of the first and second surge protection devices from ground when the input voltage is not supplied.
7 more elements
An appliance comprising:
- a load;
- and
- a surge protection circuit connected to the load, the surge protection circuit comprising:
- a voltage input circuit comprising a first line terminal and a second line terminal, the voltage input circuit configured to supply an input voltage to the first and second line terminals, wherein the voltage input circuit is an alternating current (AC) input circuit, and the input voltage corresponds to an AC input;
- a first surge protection device coupled between the first line terminal and ground;
- a second surge protection device coupled between the second line terminal and ground;
- and
- a relay circuit comprising a switch and configured to:
- connect the first line terminal to ground when the input voltage is supplied, and to disconnect the first line terminal from ground when the input voltage is not supplied;
- and
- connect the second line terminal to ground when the input voltage is supplied, and to disconnect the second line terminal from ground when the input voltage is not supplied;
- and
- a bridge rectifier capacitively coupled to the first and second line terminals, the bridge rectifier configured to convert the AC input to a direct current (DC) output for operating the switch, wherein the switch is controlled in response to the DC output and configured to electrically isolate each of the first and second surge protection devices from ground when the input voltage is not supplied.
10 more elements
A method for isolating one or more varistors in a surge protection circuit, the method comprising:
- providing the surge protection circuit, the surge protection circuit comprising:
- a voltage input circuit comprising a first line terminal and a second line terminal, the voltage input circuit configured to supply an input voltage to the first and second line terminals, wherein the voltage input circuit is an alternating current (AC) input circuit, and the input voltage corresponds to an AC input;
- a first varistor coupled between the first line terminal and ground to provide an electrical path from the first line terminal to ground;
- a second varistor coupled between the second line terminal and ground to provide another electrical path from the second line terminal to ground;
- a switch connected between the first and second line terminals and ground, the switch configured to connect each of the first varistor and the second varistor to ground when the switch is in a closed state, and to isolate each of the first varistor and the second varistor to ground when the switch is in an open state;
- and
- a bridge rectifier capacitively coupled to the first and second line terminals, the bridge rectifier configured to convert the AC input to a direct current (DC) output for operating the switch;
- and
- connecting a load to the surge protection circuit;
- applying a hi-pot voltage on the load;
- and
- controlling, via a relay circuit powered by the voltage input circuit, the switch to be in the open state to isolate each of the first and second varistors from ground in response to the hi-pot voltage.
9 more elements
Dependencies are inferred from the claim text.